Conventional computer networking in a telecommunication data center utilizes system equipment in the form of servers, switches and storage devices interconnected through a cabling infrastructure. Various types of cables, such as unshielded twisted pair (UTP), coaxial, and fiber optic, are used to interconnect the system equipment. These different types of cables can be used within the same type of network. For example, Ethernet networks or local area networks (LANs), can use many different types of cables, ranging from UTP to coaxial to fiber optic cables.
The type of cable utilized in a given telecommunications network is dictated by the network interface card of the system equipment. For example, if the network interface card is configured with small form-factor pluggable (SFP) optical transceivers, then fiber optic cabling is typically utilized. However, if the system equipment's interface card is configured with RJ-45 style modular jacks, then UTP cabling is typically utilized. Careful consideration of the type of cabling deployed and how it is deployed (i.e., the network “topology”) is important to maintain an efficient, reliable, and scalable network.
The telecommunications industry is still in the initial ramp-up stage of 10 Gigabit system equipment deployments, with 100 Gigabit deployments predicted to occur in 2011. Optics-enabled Gigabit system equipment is typically three times more expensive than UTP-enabled (i.e., electronics-enabled) Gigabit equipment. Telecommunication companies are thus often faced with the decision of deploying either cost-effective electronics-enabled Gigabit equipment configured with RJ-type modular plugs with the associated UTP cabling infrastructure, or the higher priced optics-based equipment with an optical cabling infrastructure. While deploying the less expensive electronics-based system and cabling infrastructure is appealing, the risk is that once 10 Gigabit and 100 optics-based Gigabit system equipment is deployed, the UTP cabling infrastructure will need to be re-cabled with an optical fiber cabling infrastructure.
An approach that allows for using the lower-cost electronics-based Gigabit system equipment with an optical backbone cabling infrastructure is to employ electrical-to-optical (E/O) and optical-to-electrical (O/E) conversion. Such conversion can be accomplished, for example, using Media Converter Modules (MCMs), such as the Plug & Play™ MCM available from Corning Cable Systems, LLC, of Hickory, N.C. The MCMs provide connectivity between UTP copper cabling and fiber optic cabling.
To migrate this cabling solution to a higher-data-rate optical network, such as a 10 Gigabit or 100 Gigabit Ethernet network, the MCM modules are replaced by optical interconnection modules (e.g., “reconfigurable drop modules” (“RDMs”) or “optical break-out modules”) that are patched directly into the optical backbone cabling infrastructure. In this case, the optical backbone cabling infrastructure (that includes “trunk” fiber optic cables) stays in place and does not have to be re-cabled.
For some networks, one end of the network either prefers to use or is compelled to use MCMs, while the other end prefers to use or is compelled to use optical interconnection modules. Thus, an alternative network solution involves using MCM modules at one end, optical interconnection modules at the other end, and an optical backbone cabling infrastructure connecting the two ends, thereby forming what is referred to herein as an “electrical-optical (E-O) hybrid” network configuration. In this configuration, copper-ported equipment is used at one end (or one part) of the network, and fiber-ported equipment is used at the other end (or another part) of the network. However, a complication arises in such an E-O hybrid network in that port “polarity” is not conserved, i.e., there is a configuration mismatch wherein the ports of the MCM module are not routed to the corresponding ports of the optical interconnection module.